Control for textile drafting mechanism



De@ 6 1956 J. R. WHITEHURST CONTROL FOR TEXTILE DRAFTING MECHANISM 5 Sheets-Sheet l Filed July 9, 1965 3 INVENTOR: Jos RWHxTE-HURST ATTORNEYS Dec. 6, 1966 J. R. WHITEHURST CONTROL FOR TEXTILE DRAFTING MECHANISM 5 Sheets-Sheet 2 Filed July 9, 1965 INVENTOR JOE 12. WHWEHURST @JMJ BYM, bj/@Mi ATTORNEYS Dec. 6, 1966 J. R. WHITEHURST CONTROL FOR TEXTILE DRAFTING MECHANISM 5 Sheets-Sheet 3 Filed July 9, 1965 :T m m Owm/ f mm I V b 5 WM# LI mw ,v m w l Ef@ )um M20/L1 .w W n e w 52m 4 S 5M) V l 4\/ b f W 4 H \l^/ M A|w\/5 M. WK e 2., 25 2S w M w 37 Z RY 2. a IWI olo @Em w. 5@ 5L c 7 5 l bww m w Bmw N m5 n! m u maw a w w m x l x df l w m 1 7 1 m, L 9 c J v d d d if l f mw ATTORNEY S United States Patent 3,289,255 CNTROL FR TEXTELE DRAFTNG MECIilANiSli/i .loe R. Whitehurst, 1K0. Box 35, Bessemer City, N.C. Filed July 9, 1965, Ser. No. 470,728 3 Claims. (Cl. 19-240) This application is a continuation-in-part of my copending application Serial No. 243,360, filed December l0, 1962, now Patent No. 3,243,853 and entitled Method and Means for Controlling the Output of a Textile Drafting Mechanism.

The method and means of said copending application are broadly directed to maintaining the output sliver or web issuing from the rolls of a drafting mechanism at a constant count or size, in the event of failure interruption of any textile strands or slivers being supplied to the mechanism, by sensing any reduction in the number of ends and compensatively changing the degree of draft irnparted to the ends by the drafting mechanism solely in esponse to and in accordance with the number of ends thus sensed. Specifically, the invention of said copending application effects the aforementioned change in the degree of draft by reducing the rate of production or linear speed of the output product proportionally to the number of ends whose absence is sensed while the linear speed of the ends being fed to the drafting mechanism remains constant.

It is an object of this invention to provide method and means for not only maintaining constant the size or count of the output sliver or web issuing from the rolls of a drafting mechanism by changing the degree of draft in accordance with any detected reduction in the number of ends being fed, but also to maintain the rate of production or linear speed of the issuing product substantially constant.

Another object of the present invention is to provide a method and means wherein the rate of production or linear speed of the product issuing from a drafting mechanism having a series of drafting rools is maintained constant, in addition to the count or weight per unit length of the issuing product being maintained constant, by automatically compensatively reducing the draft in the event of any reduction in the number of ends being fed without changing the speed of the delivery rolls of the drafting mechanism.

In its preferred embodiment, the apparatus of this invention includes means for detecting the absence of one or more slivers in their course to a drafting mechanism whose output drafting elements or delivery rolls are driven at a constant speed, with means embodied in clutches which are selectively rendered operative to automatically oompensatively reduce the speed of the feeding drafting elements or feed rolls a fixed amount in accordance with the number of ends Whose absence is detected.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds, when taken in connection with the accompanying drawings, in which- FIGURE 1 is a somewhat schematic perspective view of the essential elements of a drawing frame, omitting the driving connections between the front bottom drafting roll, the calender rolls and the coiler mechanism for purposes of clarity, and illustrating a preferred embodiment of the control apparatus of the present invention in association therewith;

FIGURE 2 is an enlarged longitudinal sectional view through the adjustable drive pulley associated with one of the transmission devices and being taken substantially along line 2 2 in FIGURE l;

FIGURE 3 `is a somewhat schematic side elevation of the coiler mechanism showing the driving connections between the front bottom drafting roll, the calender rolls and the coiler mechanism;

FIGURE 4 is an enlarged fragmentary longitudinal ectional view taken substantially along line 4 4 in FIGURE 1 and showing one of the driven pulleys of the transmission devices with the associated electromagnetic clutch;

FIGURE 5 is a schematic electrical diagram of the control circuit for the apparatus of FIGURE 1.

Referring more specically to the drawings, with particular reference to FIGURE 1, a group of individual slivers is drawn forwardly through a drafting mechanism or common roll section comprising a series of substantially parallel and spaced pairs of drafting rolls, the lower or bottom rolls of which are indicated at 11-14, and the upper or top rolls of which are indicated at 21-24. The drafting rolls 11, 21 are generally known as the No. 4 or back rolls, and drafting rolls 12, 22 and 13, 23 are generaly known as No. 3 and No. '2, or intermediate drafting and the drafting rolls 14, 24 are generally known as No. l or front drafting rolls. Although all the drafting rolls 11-14, 21-24 are shown in the form of fluted rolls, as is desirable, it is apparent that the upper drafting rolls 21-24, at least, may be of the smooth-faced or cushion type, without departing from the spirit of the invention The group of slivers, in this instance, includes eight individual strands or slivers indicated at Sel through S- and `may be drawn from any suitable source by the back drafting rolls 11, 21 such as a creel. In their course to the back pair of drafting rolls 11, 21, the textile slivers or strands S-1 through S- pass through a suitable xed sliver guide 25 and then move against the upper surfaces of respective sliver spoons D-l through D-S. Hooked medial portions of spoons D-1 through D-8 are pivotally supported on a stationary upper transverse bar 27. The lower rear portions of sliver spoons D-1 through ILS are normally held out of engagement with a lower transverse bar 28 as long as their upward forward portions are engaged and held in such position by the moving strands S-1 through S-S.

However, upon the parting of any one of the slivers, the corresponding spoon pivots about the upper transverse bar 27 and its overbalanced lower rear portion comes to rest against the lower transverse bar 23. Accordingly, the sliver spoons D-1 through D-S are utilized in the present instance as individual sensing or detecting elements for detecting the absence of each strand S-l. through S- being fed to the back pair of drafting rolls 11, 21, although it is apparent that sensing elements independently of the spoons D-1 through D-S may be used for the intended purpose, without departing from the spirit of the invention.`

Since the sliver spoons D-l through D-S serve as the sliver sensing elements in this instance and they are made from electrically conductive material or metal, the transverse bars 27, 28 serve as electrical contact bars or electrodes. However, since the dropping of the rear lower portions may then be in engagement with the lower transverse bar 28, for purposes to be later described, it will be observed in FIGURE 5 that the transverse bars 27, 28 are divided into a plurality of metallic or electrically conductive segments or contacts respectively designated at 32, 33 and which are separated by respective segments of insulation material indicated at 34, 35. The electrical circuit associated with the transverse bars 27, 28 will be later described.

The bottom drafting rolls 11-14 are driven at progressively increasing speeds from the rear roll 11 to the front bottom roll 14, and the top rolls 21-24 are driven by engagement with the respective bottom rolls 11-14 or by the textile material passing therebetween, as is usual. The slivers S-1 through S-S are thus drafted in their course from the rear to the front drafting rolls and then extend forwardly and downwardly and are condensed in a conventional trumpet 37 which condenses the slivers S-l through S- into a single composite sliver S which is generally of substantially the same weight per unit length as that of each of the individual strands or slivers S-1 through S-8 as it approaches the rear pair of drafting rolls 11, 21.

Trumpet 27 directs the condensed sliver S to and between a pair of calender rolls 40, 41 which are driven at a slightly greater peripheral speed than that of the front drafting rolls 14, 24. Calender rolls 40, 41 may be of the type which form parts of the coiler mechanism or, as shown in the present drawings, they may be positioned immediately above an inclined coiler tube 42 of a coiler mechanism broadly designated at 43.

`Coiler tube 42 is generally termed as a tube gear since its lower portion is integral with -a gear 44 driven to rotate about a substantially vertical axis which substantially corresponds to the axis of the open upper end of the inclined tube 42. The condensed sliver S is thus condensed and coiled into a coiler can 45, only the upper portion of which is shown in FIGURE 3.

The drive mechanism between the bottom front drafting roll 14, the calender rolls 40, 41 and the coiler mechanism 42 may be conventional and, accordingly, will now be described.

Referring to FGURE 3, it will be observed that the bottom drafting roll 14 has a shaft 56 xed thereto on which a gear 51 is suitably secured. Gear 51 meshes with a relatively large gear 52 which has a somewhat smaller gear 53 fixed in axial relation thereto and meshing with a gear 54 fixed on a jack shaft 55. A gear 56 meshes with gear 54 and with another gear 57 fixed on the corresponding end of back calender roll 4t). A gear 5S, somewhat smaller than gear 57, is also fixed on the corresponding end of back calender roll 40 and meshes with a gear 59 fixed on the corresponding end of the front calender roll 41.

Gears 52, 53 are usually in the form of change gears so that the speeds of calender rolls 40, 41 may be varied with respect to the bottom drafting roll 14. In the drafting of cotton, for example, it has been found desirable to rotate the calender rolls 4t), 41 at a peripheral speed approximately 1.04 times greater than the peripheral speed of the front drafting rolls 14, 24, thus producing a slight draft known as a tension draft in the textile material as it passes from front drafting rolls 14, 24 to calender rolls 40, 41.

It is thus seen that calender rolls 40, 41 always rotate at a peripheral speed having a fixed ratio with respect to the peripheral speed of front drafting rolls 14, 24. The coiler mechanism 43 is also driven in fixed timed relationship to the front drafting rolls 14, 24. To this end, it will be observed in FIGURE 3 that jack shaft 55 has a bevel gear `62 fixed thereon which meshes with a bevel gear 63 on the upper end of a substantially vertically disposed shaft 64. The lower end of shaft 64 transmits rotation to the usual coiler table, not shown, in a manner well known in the art. The tube gear 44 is engaged by a gear 65 fixed on the vertically disposed shaft 64 beneath bevel gear 63.

The relative speeds of the rear and No. 3 pairs of drafting rolls 11, 21 and 12, 22 and the relative speeds between the front and No. 2 pairs of drafting rolls 14, 24 and 13, 23 may also be effected in a conventional manner. In this instance, reduced corresponding ends of the bottom drafting rolls 11, 12, 13, 14 have respective gears 71-74 fixed thereon. All the gears 71-74 are spaced apart from each other. The gears 71, 72 and 73, 74 have respective pairs of change gears 75, 76 and 77, 78 interposed therebetween. Gears 71-74 engage only the respective gears -78. The gears 75, 76 rotate in fixed relationship, and gears 77, 78 rotate in fixed relationship. The relative speeds of the bottom drafting rolls 11, 12 and 13, 14 may be varied by replacing the change gears 75, 76 and 77, 78, respectively, with gears of other sizes, as is well known.

In conventional drawing frames, the front bottom roll 14- is usually driven from the main drive of the machine at a constant speed as it is in this instance, and the front drafting roll 14 transmits rotation to the second bottom drafting roll 13 substantially in the manner heretofore described. The third bottom drafting roll 12 also transmits rotation to the rear or fourth bottom drafting roll 11 by means substantially as described.

The second bottom drafting roll 13 transmits rotation to the third bottom drafting roll 12, on conventional drawing frames, through the medium of change gears which are generally termed as crown gears. However, in order to compensate for the interruption or absence of one or more strands or slivers S-1 through S-8 being fed to the drafting mechanism, according to the present method, the conventional crown gears are omitted and the apparatus of the present invention, to be presently described, is substituted for the crown gears. Accordingly, a main drive shaft 80 is suitably journaled on the frame of the drawing frame and is operatively connected to the bottom delivery drafting roll 14 through the medium of a pair of pulleys 81, 82 about which an endless V-belt S3 is entrained. Pulley 81 is fixed on drive shaft 80 and pulley 82 is fixed on shaft 50 extending from the end of front bottom drafting roll 14 opposite front gear 74.

Drive shaft 80 may be driven by any suitable means and, in this instance, the outer end of drive shaft 80y has a pulley 85 fixed thereon which is engaged by `an endless belt `86 which also engages a pulley 87 of an electric motor 90. As shown in FIGURE 5, electric motor 90 has lead wires or conductors 91, 92, 93 extending therefrom which are adapted to be connected to a suitable source of electrical energy or alternating current, not shown.

Drive shaft 80 is connected to a shaft 84 of bottom back drafting roll 11 through the medium of a plurality of transmission units which are operative, one at a time, according to variations in the number of strands or slivers being properly directed through the drafting mechanism. As illustrated in FIGURES 1 and 5 of the drawings, three such transmission units are provided for connecting main drive shaft Si) to the bottom back roll shaft 84 and are generally designated at 95, 96, 97. As will be later described more in detail, transmission unit 95 transmits rotation from shaft Si) to shaft 84 at the slowest predetermined speed when all of the desired number of slivers are being properly fed to the drafting mechanism. Upon the loss or absence of any one of the strands or slivers S-1 through S-8 being detected by one of the sliver spoons or sensing elements D-1 through D-i, transmission unit 95 is rendered inoperative and transmission unit 96 becomes operative to transmit rotation from shaft 8i) to shaft 34 at an intermediate but faster speed than that which is transmitted by transmission unit 95 'and at a speed proportional to the number of slivers remaining intact as compared to the original number of slivers which should be fed to the drafting mechanism.

Upon the absence of any two of the slivers S-1 through S-8 being detected by a corresponding pair of the sliver spoons or sensing elements D-l through D-B, such as by the parting of said two slivers, transmission unit 96 is then rendered inoperative, transmission unit 95 remains inoperative, and transmission unit 97 is rendered operative to then transmit rotation from shaft 8l) to shaft 84 at a still faster speed than that which is transmitted by the transmission unit 96.

When transmission unit 97 is rendered operative, it transmits rotation to shaft 84 so the speed of back bottom roll 11 is proportionally faster than that imparteA ansa thereto by transmission unit 95 in accordance with the number of slivers S-1 through S8 (six in this instance) which then remain intact as compared to the original number of strands or slivers which should be fed to the drafting mechanism. From the foregoing, it is apparent that the so-called crown draft between the two intermediate pairs of drafting rolls 12, 22 and 13, 23 is constant as long `as the desired number of slivers are being fed to the drafting mechanism and is proportionally reduced in Iaccordance. with any decrease in the number of such slivers relative to the total number which should be fed thereto. Thus, the sliver S being formed is of substantially uniform weight per unit length, and the rate of output of the drafting mechanism is constant, iat all times.

In the illustrated embodiment of the invention, each transmission unit 95, 96, 97 may comprise an adjustable pitch V-pulley 100 (FIGURES 1 and 2) fixed on main drive shaft 80 and engaged by an endless V-belt 101. Each V-belt 101 also engages a corresponding V-pulley 102 which is journaled or loosely mounted `on the shaft 84 extending from back bottom drafing roll 11 (FIG- URES 1 and 4). Each V-pullcy 102 is adapted to be independently coupled or secured in fixed relation to shaft 84 through the `meduim of an electrically operable or electromagnetic clutch broadly designated at 103. A suitable belt tensioning device may be provided between each pair of pulleys 100, 102 for maintaining the belts 101 under tension, but since such tensioning device forms no part of the present invention, it is not illustrated or described herein.

Although the pulleys 100, 102 and belt 101 are shown in FIGURE 1, it is apparent that suitable gears may be substituted for the pulleys 100, 102 with suitable change gea-rs being substituted for the corresponding belts 101 therebetween, without departing from the spirit of the invention.

In the disclosed embodiment, all the pulleys 100 and 81 mounted on drive shaft 80 are preferably of the adjustable type so that the peripheral speed of front drafting rolls 14, 24 may be adjusted in accordance with the linear speed at which the slivers S-1 through S48 are to be delivered from the drafting mechanism and so that the different speeds imparted to the back bottom drafting roll 11 by transmission units 95, 961, 97 may be accurately determined in accordance wit-h the number of slivers passing through the drafting mechanism, the desired crown draft, and the characteristics of the particular textile material being drafted.

By way of example, 'a detailed illustration of one of the adjustable pulleys 100 is shown in FIGURE 2. Adjustable pulley 81 may also be constructed in the same manner as the pulley shown in FIGURE 2. Each pulley 100 includes a pair of flanges or cones 104, 105 between which the corresponding belt 101 is positioned. Flange 104 -has an elongate hub 106 integral therewith and keyed on shaft 00, as at 107. Hub 106 also may be secured to shaft 00 by means of a set screw 110. Hub 106 is externally threaded and has a hub portion 111 of flange 105 threaded thereon which may be locked in the desired adjusted position by a lock nut 112 threaded on the hub 106 of flange 104.

As heretofore stated, each V-pulley 102 is adapted to be coupled to -shaft 84 upon actuation of the corresponding electromagnetic clutch 103. Since all the clutches 103 may be identical, only one of them is shown in detail in FIGURE 4. Also, since various types of clutches may be used for the intended purpose, the clutch is shown in FIGURE 4 by way of illustration only, as being of a type such as is manufactured by Ste-arns Electric Corporation, Milwaukee 2, Wisconsin, under their number 5.5 SMR and `as illustrated on their drawing No. C3105-I, dated May 17, 1961.

In this instance, each clutch 103 comprises a stator or housing 115 which loosely encircles shaft 84 and within which the hub 116 of 'a driven rotor 117 is loosely positioned so rotor 117 and hu-b 116 may rotate relative to stator 115. Accordingly, a suitable bearing 120 is provided between stator 115 and vhub 116. In order to prevent rotation of stator 115, it may be fixed to a bracket 121 suitably secured to any fixed part of the machine, such `as a portion of the frame of the drawing indicated at F in FIGURE 4, The driven rotor 117 is encircled by a magnetic coil 123 fixed to driven rotor 117.

Since the clutch 103 shown in FIGURE 4 is that clutch associated with transmission unit of FIGURE 1, the stator thereof has a pair of electrical conductors or wires a, 1 1 connected thereto and which extend into stator 115. The other two clutches 103, `associated with transmission units 96, 97, have respective conductors b, b-1 and c, c-1 connected thereto (FIGURE 5) which -correspond to conductors a, a-l. In this instance, the inner surface of each coil 123 may be provided with a pair of slip rings d, e (FIGURE 4) thereon to which opposed ends of coil 123 are suitably connected, and which engage respective brushes f, g secured to, but insulated from, the adjacent face of stator 115 and to which corresponding ends of conductors a, a-1 are suitably connected.

In FIGURE 4, the hub 116 of rotor 117 is keyed to shaft 04, as at 125, and is also secured thereto by a set screw 126. As heretofo-re stated, each pulley 102 is loosely mounted on shaft 04. In this instance, pulley 102 is shown in FIGURE 4 as being rotatably Vmounted on shaft 04 by means of anti-friction bearings 130, 131. The pulley 102 of FIGURE 4 is prevented from having endwise movement relative to stator 115 and driven rotor 117 by a collar 132 fixed on shaft 04, as by means of a set screw 133, and which engages the inner race of outer bearing 130.

The inner nace of inner bearing 131 bears against a shoulder 134 formed cn the inner surface of driven rotor 117. The hub of pulley 102 is encircled by an annular plate or driving rotor 135 suitably keyed to the hub of the corresponding pulley 102, as at 136. It should be noted that driving rotor 135 is positioned closely adjacent driven rotor 117 and coil 123 and may have limited axial movement relative thereto, such axial movement being limited by a suitable limiting ring 137 encircling the hub of the correspon-ding pulley 102 and being spaced outwardly from the corresponding end of driven rotor 117 and its coil 123.

From the foregoing, it is apparent that all the pulleys 102 and shaft 04 may rotate relative to each other whenever corresponding coils 123 are not activated or energized. However, upon a corresponding coil 123 being energized, the corresponding driving rotor 135 is pulled tightly against driven rotor 117 and coil 123 so that the adjacent pulley 102 (which rotates continuously throughout operation of the machine) then transmits rotation to shaft 84 through the medium of the corresponding coil 123, driven rotor 117 and hub 116.

As heretofore stated, whenever one or more of the strands or slivers S-1 through S-S is parted as it approaches the drafting mechanism, the speed of the back drafting rolls 11, 21 is increased accordingly, and the front rolls 14, 24 continue rotating at a constant speed. Therefore, it is apparent that clutch 103 of transmission unit 95 must be deactivated and clutch 103 of transmission unit 96 must be activated upon any one of the strands S-1 through S-S becoming parted and, further, upon an additional strand or sliver becoming parted, regardless of which strand it might be, so that two strands are then parted at the same time, the clutches 103 of transmission units 95, 96 must be inoperative while the clutch 103 of transmission unit 97 is actuated.

It is to be noted that other similar transmission units, not shown, may function whenever three or more of the strands become parted, but the three transmission units 95, 96, 97 would probably be sufficient for all practical purposes when taking into consideration the original number of strands or slivers being fed to the drafting mechanism and the extent to which the crown draft between the second and third pairs of drafting rolls 12, 22 and 13, 23 must be decreased as the number of slivers being fed to the drafting mechanism decreases.

In order to effect actuation of clutch 163 of transmission unit 96 whenever any one of the slivers S-1 through S-S becomes parted, and to effect actuation of clutch 163 of transmission unit 97 whenever any two of the slivers S-1 through S-S becomes parted, a special control circuit is provided (FIGURE which is motivated by a suitable direct current power supply 144, in this instance. To this end, it will be observed in FIGURE 5 that each metallic segment 33 of bottom transverse Contact bar 2S has one end of a resistor connected thereto, the resistors corresponding to sliver spoons D-1 through D- being respectively designated at R-1 through R-. All the resistors R-1 through R-8 are arranged in parallel relationship and are connected to a common conductor 140.

Each metallic segment 32 of upper transverse contact bar 27 has a corresponding conductor connected thereto, the conductors corresponding to the sliver spoons D-1 through D- being respectively designated at W-1 through W-S. The latter conductors are also arranged in parallel, and the ends thereof opposite from metallic segments 32 are connected to a common conductor 141 to which one end of a conductor 142 is connected. The other end of conductor 142 is connected to a conductor 143 extending from one side of the output of power supply 144. The other side of the output of said power supply 144 has a conductor 11i-6 leading therefrom to ground. The input of power supply 144- has conductors 156, 151 leading therefrom to lead conductors 91, 92 heretofore described.

A conductor 152 extending from conductor 1416 has a conductor 153 extending therefrom t0 one side of the coil 154 of a low-voltage relay 155. The other side of coil 154 is connected to ground by means of a conductor 156. A normally open switch 157 of a suitable time-delay-relay 166 may be interposed in conductor 153, although relay 166 and its switch 157 may not be required in all instances, as will be later explained. If switch 157 is not required in the particular installation of the control apparatus, it is apparent that conductor 153 then may extend directly to the coil 154l of low voltage relay 155 without interruption. The end of conductor 152 opposite from conductor 140 is connected to one end of the coil 161 of time-delayrelay 166 and the other end of coil 161 has a conductor 162 extending therefrom to ground. Low voltage relay 155 includes a normally open switch 163 which is closed upon energization of coil 154 and then establishes contact between a pair of conductors 164, 165.

Conductor 164 is connected to a medial portion of conductor 156 and is thus connected to ground. Conductor 165 is connected to one side of a double-throw switch 166 of a high voltage relay 167 which also includes a coil 170. When coil 176 is not energized or subjected to suficiently high voltage, switch 166 normally maintains contact between conductor 165 and a conductor 171 leading to a medial portion of a coil 172 of a relay 173. One end of coil 17,2 has the conductor 143 connected thereto and the other end of coil 172 has one end of a conductor 174 connected thereto and extending to high voltage relay 167. When relay 167 is activated, switch 166 breaks Contact between conductors 165, 171 and makes contact between conductors 165, 174.

Coil 176 of high voltage relay 167 has conductors 175, 176 connected to opposite ends thereof, conductor 175 being connected to ground. The end of conductor 176 opposite from coil 176 is connected to a medial portion of conductor 153 at a point between switch 157 and coil 154 of low voltage relay 155.

Relay 173 is provided for controlling three parallel switches A, B, C which control energization of the clutches 103 of the respective transmission units 95, 96,

97. Switch A is normally closed and switches B, C are normally open. Although relay 173 may be of any desired construction, it is shown in the form of a solenoid having a solenoid plunger 181 to the free end of which switch A is suitably secured and which is normally urged to extended position by a tension spring 182.

Plunger 161 has a pair of longitudinally spaced switch actuators 183, 184 fixed thereon which are adapted to successively and independently engage and close the respective switches B, C so that, when only one half or a portion of coil 172 is energized, only switch B will be closed. On the other hand, when the entire length of the coil 172 is energized, plunger 181 is moved so that actuator 183 moves out of engagement with switch B and actuator 184 moves into engagement with switch C. When either actuator 183 or 184 closes the corresponding switch B or C, it is apparent that switch A is opened.

Corresponding sides of switches A, B, C have the ends of the respective conductors a, b, c opposite from clutches 163 of the respective transmission units 95, 96, 97 connected thereto. The other sides of switches A, B, C have respective conductors 185, 186, l197 connected thereto. Conductor 185 leads from switch A to lead conductor 92, and the ends of conductors 156, 187 opposite from switches B, C are connected to conductor 185.

In order that an attendant may quickly determine which of the three clutches 103 is energized, and thus determine whether one or more of the slivers S-1 through S-S are parted and to determine the urgency of promptly piecing up any parted slivers, a suit-able electrically operated warning device may be arranged to operate as each respective clutch is actuated. In this instance, the warning devices associated with the respective power transmission units 95, 96, 97 are shown in the form of incandescent lamps 191, 192, 193 and may be of distinguishing colors. For example, the lamps 191, 192, 193 may be green, amber and red, respectively.

In order that lamps 191, 192, 193 may be energized only at such times as the clutches 163 of the respective transmission units 95, 96, 97 are energized, ylamp 191 is interposed in a conductor 194 extending from lead conductor 92 to a medical portion of conducto-r a; lamp 192 is interposed in a conductor 195 extending from lead conductor 92 to the side of switch B opposite from conductor b; and lamp 193 is interposed in a conductor 196 extending from lead conductor 92 -to that side of switch C opposite from conductor c. The ends of conductors a-1, b1, c-1 opposite from clutches 103 are connected to lead conductor 91.

Method of operation It is well known that many different types or blends of textile fibers are drafted through the drafting mechanisms of drawing frames, and the number of ends of sliver being fed to `a drafting mechanism may vary from as few as 4 ends up to and exceeding 14 ends of sliver. Also, the total draft to be produced in the slivers being drafted may vary considerably in accordance with the number of slivers being fed to the drafting mechanism and the characteristics of the slivers and the fibers of which they are formed. However, in `order that the invention may be clearly understood, it is to be assumed, in this method of operation, that eight 50-grain cotton slivers are the desired number to be fed to the drafting mechanism and that a single SO-grain composite sliver is formed therefrom upon leaving the front drafting rolls 141, 24, thus indicating that there may be `a draft of eight while all eight of `the slivers S-1 through S-S are being properly fed to the back drafting rolls 511, 211.

It follows that, upon the parting of a single one of the slivers, a draft of seven would then be required between the back rolls 11, 21 and the front rolls 14, 24 in order to continue to produce a SO-grain sliver, and upon the parting of any two of the strands or rslivers S-1 through S-S, a draft of six would be required between the back Si rolls 11, 21 and the front rolls 14, 24 in -order to continue to produce a Sil-grain sliver therefrom.

In the following example, it is to be assumed that all the bottom drafting rolls 11-14 are of the same diameter and that, when vall the slivers S-1 through S-8 are being fed by the back drafting rolls 111, 21, they are moving at a linear speed of approximately 100 feet per minute. It follows that, since the eight slivers S-1 through S-8 are being fonmed into a single sliver S of substantially the same size as each of said eight slivers, the lowest peripheral speed imparted to the front drafting rolls 14, 24 would be approximately eight times that of the peripheral speed of the back drafting rolls 11, 21; i.e., 80()- feet per minute. The speed of the back drafting rolls 11, 21 would be increased by approximately 14 feet per minute with the `loss of one end and by approximately 33 feet per minute with the loss of two ends.

From the foregoing, it is apparent that the ratio between the speeds of pulley 82 and pulley 102 of transmission unit 95 should ybe lapproximately 8 lto 1, the ratio between the speeds of pulley 82 and pulley 1112 of transmission unit 96 should be approximately 7 to 1; and the ratio between the speeds of pulley 82 and pulley 102 of transmission unit 97 -should be approximately 6 to 1. It may be assumed, therefore, that drive shaft Sill is driven at a ratio relative to pulley 82 of approximately the square root of the aforementioned 8 to 1 ratio; i.e., 2.83 to 1. Thus, the ratio of the effective diameter of pulley 1110 to that of pulley 102 of transmission unit 95 would be `approximately 2.83 to 1, and the ratio of the effective diameter of pulley 82 to that of pulley 81 would also be approximately 2.83 4to 1.

Since the relative speeds of the two bottom drafting rolls 11, 12 and the relative speeds of the two bottom drafting rolls 13, 14, and the draft effected thereby in the strands passing thereover, remains constant, and `it is necessary, in this example, to produce a :total draft of seven whenever a single strand lof the group S-1 through S-S becomes parted, it follows that the ratio between pulleys 100i, 102 of the intermediate speed transmission unit 96 is equal to seven divided by 2.83 or 2.47 to 1.

Since the high speed power transmission unit 97 is actuated upon the absence of any two slivers in group S-1 through 5 8 being detected, it follows that the ratio between the pulleys 108, 4102 of transmission unit 97 should be equal to six divided by 2.83 or 2.13 to 1.

In the present example, in which an eight draft is to be effected in the eight slivers S-1 through S-8 as they pass through the drafting mechanism, since the square root of eight is approximately 2.83, the ratio between the peripheral speeds of the front bottom drafting roll 14 and the No. 2 bottom drafting roll 13 is approximately 2.83 to 1. As heretofore stated, this is the assumed ratio between the eeifctive diameters of pulleys 81, 82. It may be assumed that the ratio between the peripheral speeds of the No. 3 bottom drafting roll 12 and the rear bottom drafting roll 11 is approximately 1.45 to `1. Thus, `the ratio between the peripheral speeds of the second and third bottom rolls 13, 12 is 8 draft m-LQS (approximately) This is in accord with the fact that the aforementioned ratio between the diameters of the two pulleys t100, 1102 of slow speed transmission unit 95 is approximately 2.83 to l, since 1.45 1.95=2.83 (approximately).

In normal operation, in which all of the desired number of ends of slivers S-1 through S-8 are being properly directed to the drafting mechanism, none of the sliver spoons or sensing elements D-1 through D-8 are in engagement with a segment 33 of the lower transverse contact bar 28 and, thus, the control circuit remains quiescent so that switch A is closed and current fiows through the clutch 103 of slow speed transmission 95 and through the warning device or lamp 191 associated therewith. Thus, inthe present example, power transmission unit is active while transmission units 96, 97 are inactive and rotation is being transmitted to rear bottom drafting roll 11 at a peripheral speed of approximately feet per minute while front bottom roll 11 is rotating at a peripheral speed of 800 feet per minute.

Before proceeding further with this description of the operation of the apparatus, exemplary values will be given to certain elements of the control circuit in FIGURE 5. It is to be assumed that the power supply 144 converts the alternating current directed thereto through conductors 159, 151 to a 90 volt, 2 ampere, direct current and that each of the resistors R-1 through R-8 has a resistance of 10 ohms. It shall also be assumed that the coils 161, 154 of the relays 160, 155 will become operative to close the respective switches 157, 163 upon being subjected to an electrical impulse of approximately 70 volts as well as any additional voltage to which they may tbe subjected. However, the coil 170 of relay 167 should be so wound that, although current may flow therethrough when coil 178 is subjected to an electrical impulse having a magnitude of less than 8O volts, the magnetic ux produced by coil 170 will be insufficient to attract the armature or switch 166 thereto until the coil 1711 is subjected to a minimum of 80 volts.

Upon the parting of any one of the slivers S-1 through S-S permitting the corresponding sliver spoon to drop against a segment 33 of lower transverse bar 28, current flows from the power supply 144 at 90 volts through the corresponding sensing element or sliver spoon and through one of the resistors R-l through R-S. In this instance, it shall be assumed that strand S-4 has parted and, therefore, current will be flowing through resistor R-4.

Current ows from resistor R-4 through coil 161 of time-delayrelay 160. As heretofore stated, the coil 161 of relay becomes active when a relatively low voltage of, say 70 volts, is applied thereto. According to Ohms law, since a single resistor R4 is then active in the control circuit, the resistance of resistor R-4 effects a voltage drop of 2O volts across resistor R-4. When this 20 volts is subtracted from the 90 volts directed from the power supply 144, it follows that the voltage being applied in the control circuit is then 70 volts.

The time-delay-relay 160 may be of any desired or conventional construction and, therefore, details thereof are omitted from the present disclosure. Time-delayrelay 160 may be of a type substantially as disclosed in FIGURE 18 of U.S. Patent No. 2,752,273, granted to George W. Mitchell on June 26, 1956, for example. In any event, time-delay-relay 160 should be of a type which will close switch 157 at a predetermined interval following the detection of the parted strand by a corresponding one of the sliver spoons S-l through S-8, e.g., at the instant at which the trailing end of the parted strand reaches the nip of the rear drafting rolls 11, 21. As heretofore stated, since the slivers S-1 through S-8 are moving at a high rate of speed in their course to the drafting mecha* nism, the time-delay-relay 1611 may be omitted in most instances.

In either event, current flows through the coil 154 of low voltage relay 155, thus closing switch 163 so that current flows through approximately one-half of the coil 172 of relay 173. It is apparent that current flows through approximately one-half of the coil 172 in this instance, because of the fact that switch 166 is connected across conductors 165, 171. Although conductor 176 connects the coil 170 of relay 167 to conductor 153 at this time, the low voltage of 70 volts applied to coil 170 is insufficient to cause switch 166 to movedownwardly in FIGURE 5.

As heretofore stated, when the upper portion of coil 172 in FIGURE 5 is energized, this applies sufficient pulling force to plunger 181 only to open switch A and close 1 1 switch B. Thus, lamp 191 and the clutch 103 are transmission unit 95 are deenergized and lamp 192 and the clutch 103 of transmission unit 96 are energized a current ows through switch B.

It is thus seen that, upon the parting of any one of the slivers S-1 through S-8 while all the remaining slivers remain intact, transmission unit 95 is rendered inoperative as intermediate transmission unit 96 is rendered operative for driving the |back rolls 11, 21 at an intermediate or faster speed than that at which they were driven by the transmission unit 95; i.e., approximately 114 feet per minute in this example.

Now, upon any two of the slivers S-1 through S-S becoming parted so that two ends are down at the same time, two of the resistors R-1 through R-S are rendered active in parallel in the control circuit. For purposes of description, it shall be assumed that the two slivers 5 4, S-S have become parted and the rear portions of the corresponding sliver spoons or sensing elements D-4, D-5 have dropped into engagement with adjacent segments 33 of lower transverse bar 28. Thus, current will flow from supply 144 through both resistors R-4, R5 to conductor 140.

Since, according to Ohms law, the voltage drop across two resistors in parallel is equal to the value of the two resistors in ohms multiplied by each other, divided by the value of the two resistors added together, and then multiplied by the amperes of current, the voltage drop across the two resistors R-4, R-5 would then be ten volts; that is 10 X 2 lO-l-lO This voltage drop of ten volts subtracted from the 90 volts at the power supply 144 results in 80 volts being applied to coils 161, 154, 170 of all three relays 160, 155, 167. Thus, both switches 157, 163 would again be closed in a manner heretofore described, or they would remain closed if one of the two ends had parted prior to the other end being parted.

Since the coil 170 of high voltage relay 167 will then have 80 volts applied thereto, the switch 166 would move downwardly in FIGURE 5 so the entire length of the coil 172 of relay 173 would then be energized. In this instance, it will be noted that conductor 174 is then connected to ground through switches 166, 163.

As heretofore stated, upon energization of the entire length of coil 172 of relay 173, the pulling force applied to plunger 181 by coil 172 moves plunger 181 to where the switch C is closed as actuator 184 engages the same, and switches A, B are then opened. Thus, upon any two of the slivers S-1 through S-S being parted, the two clutches 103 of transmission units 95, 96 are deenergized as the clutch 103 of high speed transmission unit 97 is energized so that the Iback drafting rolls 11, 21 then rotate at a relatively high speed which is approximately 133 feet per minute in this example.

Thus, the draft between the second and third pairs of rolls 13, 23 and 12, 22 is reduced so that the six remaining strands or slivers, e.-g, S-1, S-2, S-3, S-6, S--7 and S-8, will be combined into a single sliver S of substantially the same weight as the previously formed sliver and the rate at which the sliver S would be delivered to the coiler can 45 would then be the same as it was when all of the slivers S-1 to S-8 were intact, because said six remaining slivers being directed to the drafting rolls 11, 21 would be moving at a faster linear speed than they were when all the original number of slivers were being directed to the drafting mechanism or Iback drafting rolls 11, 21.

It is thus seen that the sliver spoons D-1 through D-S collectively form a measuring device whose indicating value varies only according to the number of strands passing therethrough and wherein an electrical impulse is obtained from said value and the magnitude of the iml0 volts pulse varies according to said value as effected through the medium of the resistors R-1 through R-S. Thus, the energy derived from such impulses is utilized to effect the drive of the back pair of drafting rolls 11, 21 at speeds corresponding to said impulses.

As heretofore stated, although additional power transmission units may be provided between shafts 80, 84 so as to be rendered operative upon the par-ting of three or more of the strands being fed to the drafting mechanism, such an arrangement would not generally be required and therefore, additional power transmission units are not shown in the present drawings.

It should be noted that, upon the parting of more than two strands in the embodiment illustrated in FIGURES l and 5, the control circuit would `continue to operate in the manner described with respect to power transmission unit 97, since each time a resistor is rendered active in the control circuit in addition to said two resistors, the voltage applied to the control circuit is increased due to the decrease in the voltage drop across the resistors. Thus, the warning lamp 193 would remain energized and, of course, whenever the warning larnp 193 is energized, the attendant should piece up any broken ends promptly.

It is thus seen that I have provided a novel method for automatically controlling the weight per unit length of textile material issuing from a drafting mechanism and wherein the amount of draft imparted to the textile material by the drafting mechanism is automatically reduced in accordance with any reduction in the number of ends or slivers being fed thereto and also wherein the draft imparted to the textile material is increased upon restoration of such parted ends and wherein the linear speed of the sliver or web being formed .may remain constant regardless of any reduction in the number of slivers being directed to the drafting mechanism so the sliver or web for-med from the group of slivers will continue to be of substantially uniform weight per unit length.

In the drawings and specification there has been set forth a preferred embodiment of the invention and, although specific terms are employed, they are Aused in a generic and descriptive sense only and not for purposes of limitation, the scope of-the invention being defined in the claims.

I claim:

1. Apparatus for driving a series of spaced pairs of drafting rolls and controlling the angular speed of the back pair of rolls in said series relative to the front pair of yrolls to produce textile material of substantially uniform weight per unit length from a group of textile strands irrespective of the absence of at least one of the strands in the group, said apparatus comprising a continuously driven main shaft,

a front shaft fixed to one of the front rolls, first and second pulleys fixed on the main shaft and the front shaft, respectively, and an endless belt engaging and interconnecting said pulleys for transmitting rotation from the main shaft to the front shaft and thus to the front rolls at a constant angular speed,

a normally active slow speed transmission means coupling said main shaft to said back rolls for driving Isaid back rolls at a given relatively slow speed while all the strands in said group are passing through said rolls,

at least one normally inactive transmission means interposed between said main shaft and said back rolls and being arranged, when active, to drive said back rolls at a predetermined fast speed relative to said slow speed,

means for detecting only the absence of each of any of said strands in their course to at least one of said pairs of rolls, and

means operatively connecting said detecting means to said normally active and normally inactive transmission means and being responsive to the detection of the absence of at lleast one of said strands by said detecting means for inactivating said normally active transmission means and activating said normally inactive transmission means.

2. Apparatus for driving a series of spaced pairs of drafting rolls and controlling the angular speed of the back pair of rolls in said series relative to the front pair of rolls to produce textile material of substantially uniform weight per unit length from a group of textile strands irrespective of the absence of at least one of the strands in the group, said apparatus comprising a continuously driven main shaft,

a front shaft iixed to one of the front rolls, first and second pulleys fixed on the main shaft and the front shaft, respectively, and an endless belt engaging and interconnecting said pulleys for transmitting continuous constant speed rotation to said front rolls from said main shaft,

a back shaft xed to one of said back rolls,

a plurality of clutches, including a iirst and a second clutch mounted on said back shaft, each clutch cornprising a driving member including a clutch pulley, a driven member, and electrically operable means for coupling together said driving and driven members in each clutch for transmitting rotation from the clutches to said 'back shaft,

an additional pulley corresponding to each clutch pulley and :fixed on said main shaft,

an endless belt engaging and interconnecting each clutch pulley and its said corresponding additional pulley, the ratio of the eective diameters of the pulleys associated with the first clutch being su-ch relative to the ratio of those pulleys associated with the second clutch that said iirst clutch transmits slow speed to the back shaft and said second clutch transmits relatively fast speed to said back shaft,

a sensing element for sensing only the absence of each of any of said strands,

means normally activating said electrically opera'ble means of only said first clutch, and

means responsive to said sensing elements sensing the absence of a strand for deactivating the electrically operable means of Said first clutch and activating the electrically operable means of said second clutch. 3. The apparatus according to claim 2 including a third clutch mounted on said back `shaft and having a driving member including a clutch pulley, a driven member, and normally inactive electrically operable means for coupling together, when active, the latter driving and driven members to transmit rotation from said third clutch to said 'back shaft,

another pulley fixed on said main shaft, another endless Ibelt engaging and interconnecting said last-named pulleys associated with said third clutch, the ratio of the eifective diameters of the last-named pulleys relative to the ratio of those pulleys associated With said second clutch being such that said third clutch transmits a faster speed to said back shaft than said second clutch, and `said responsive means also being responsive to at least two of said sensing elements sensing the absence of respective strands for activating the electrically operable means of said third clutch while rendering inactive the electrically operable means of said rst and second clutches.

References Cited bythe Examiner UNITED STATES PATENTS 2,964,803 12/1960 Robinson 19-240 FOREIGN PATENTS 906,795 9/ 1962 Great Britain.

MERVIN STEIN, Primary Examiner. DONALD W. PARKER, Examiner'. D. NEWTON, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N6. 3,289,255 December 6, 1966 Joe R. Whitehurst It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

In the heading to the printed specification, line 4, for "Joe R. Whitehurst, P. O. Box 35, Bessemer City, N. C." read Joe R. Whitehurst, Bessemer City, N. C., assignor to Ideal Industries, Inc., Bessemer City, N. C., a corporation of North Carolina column 1, line 16, after "failure" insert line 19, for "and", first occurrence, read the line 21, after "drafting", first occurrence, insert rolls column 4, line 31, for "front" read from column 5, line 2l, for "drafing" read drafting column 6, line 6,

after "drawing" insert frame column 8, line 42, for "medical" read medial column 9, line 54, for "eeffctive" read effective column 11, line 3, for "a" read as line 22, before "supply" insert power Signed and sealed this 26th day of September 1967.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attestng Officer Commissioner of Patents 

1. APPARATUS FOR DRIVING A SERIES OF SPACED PAIRS OF DRAFTING ROLLS AND CONTROLLING THE ANGULAR SPEED OF THE BACK PAIR OF ROLLS IN SAID SERIES RELATIVE TO THE FRONT PAIR OF ROLLS TO PRODUCE TEXTILE MATERIAL OF SUBSTANTIALLY UNIFORM WEIGHT PER UNIT LENGTH FROM A GROUP OF TEXTILE STRANDS IRRESPECTIVE OF THE ABSENCE OF AT LEAST ONE OF THE STRANDS IN THE GROUP, SAID APPARATUS COMPRISING A CONTINUOUSLY DRIVEN MAIN SHAFT, A FRONT SHAFT FIXED TO ONE OF THE FRONT ROLLS, FIRST AND SECOND FULLEYS FOXED OR THE MAIN SHAFT AND THE FRONT SHAFT RESPECTIVELY, AND AN ENDLESS BELT ENGAGING AND INTERCONNECTING SAID PULLERYS FOR TRANSMITTING ROTATION FROM THE MAIN SHAFT TO THE FRONT SHAFT AND THUS TO THE FRONT ROLLS AT A CONSTANT ANGULAR SPEED, A NORMALLY ACTIVE SLOW SPEED TRANSMISSION MEANS COUPLING SAID MAIN SHAFT TO SAID BACK ROLLS FOR DRIVING SAID BACK ROLLS AT A GIVEN RELATIVELY SLOW SPEED WHILE ALL THE STRANDS IN SAID GROUP ARE PASSING THROUGH SAID ROLLS, AT LEAST ONE NORMALLY INACTIVE TRANSMISSION MEANS INTERPOSED BETWEEN SAID MAIN SHAFT AND SAID BACK ROLLS AND BEING ARRANGED, WHEN ACTIVE, TO DRIVE SAID BACK ROLLS AT A PREDETERMINED FAST SPEED RELATIVE TO SAID SLOW SPEED, MEANS FOR DETECTING ONLY THE ABSENCE OF EACH OF ANY OF SAID STRANDS IN THEIR COURSE TO AT LEAST ONE OF SAID PAIRS OF ROLLS, AND MEANS OPERATIVELY CONNECTING SAID DETECTING MEANS TO SAID NORMALLY ACTIVE AND NORMALLY INACTIVE TRANSMISSION MEANS AND BEING RESPONSIVE TO THE DETECTION OF THE ABSENCE OF AT LEAST ONE OF SAID STRANDS BY SAID DETECTING MEANS FOR INACTIVATING SAID NORMALLY ACTIVE TRANSMISSION MEANS AND ACTIVATING SAID NORMALLY INACTIVE TRANSMISSION MEANS. 